<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        function tt() {
            var l = 9
        }
        for (var i = 1; i < 0;) {
            var s = 5
        }
        if (1) {
            var j = 0
            let sb = 3
        }
        console.log(i)//这个i是全局的
        console.log(s)
        console.log(j)
        console.log(typeof (tt))
        console.log(sb)
    </script>
</body>

</html>